I just gave him a letter increasing his rent and I asked him to sign the acknowledgment of receipt and he outright refused.  

If they fail to acknowledge your claim, then your contractor license board consumer department can help you out.

@Josh Haney Even if you you have the ability to raise capital, as you acknowledged you lack experience.

The HOA won't even acknowledge that our 2005 Rules & Regs ever existed, won't provide us with updated Rules & Regs or even confirm whether a new version exists. 

If it is you and you go overboard to acknowledge the short coming and make it right than the guest will most likely forget about it and move on, if you blow it off the guest will make it a big deal and a big headache for you".

If the guest has a valid point make some changes, and in the response acknowledge you we're unaware and plan to adjust.

Can I include something in the Rental Agreement where they would sign, acknowledging the stair issue and that we are not liable? 

Remember, everyone starts somewhere, and acknowledging your beginner status can foster genuine connections with seasoned investors who are often more than willing to offer guidance and share their experiences.Local meetups serve as invaluable hubs of knowledge, bringing together like-minded individuals who are active in the same market you aim to enter or are already operating in.

I also have every tenant that is listed on the lease initial every page of my lease so there is no question that they have acknowledged everything that is included.

I'm not sure why so many people mention this without acknowledging that you will be underwater with just 20% down in major cities or anywhere appreciating especially in San Francisco as Carlos mentioned and at current prices and interest rates. 20% down does not equal 20% returns.